Page 27 - Electrician - TT (Volume 1)

ELECTRICIAN - CITS ELECTRICIAN - CITS

Fig 11 Fig 12

13 Centre punch (Fig 13) BIS 7177
The size is given by its length and diameter of the body.
Eg. 100 mm x 8 mm. The angle of the tip of the centre punch is 90°.
It is used for marking and punching pilot holes on metals. It is made of tool steel and the ends are hardened and
tempered.
14 Mallet (Fig 14)
The mallet is specified by the diameter of the head or by the weight.
eg. 50 mm x 150 mm

75 mm x 150 mm or 500gms, 1 Kg.
It is made out of hard wood or nylon. It is used for driving the firmer chisel, and for straightening and bending of
thin metallic sheets. Also it is used in motor assembly work.

Fig 13 Fig 14

15 Flat cold chisel (Fig 15) BIS 402
Its size is given by the nominal width and length.
ie. 14 mm x 100 mm

15 mm x 150 mm
20 mm x 150 mm
The body shape of a cold chisel may be round or hexagon.
The cold chisel is made out of high carbon steel. Its cutting edge angle varies from 35° to 45°. The cutting edge
of the chisel is hardened and tempered. This chisel is used for making holes on wall etc.
16 Rawl plug tool and bit (Fig 16)
Its size depends upon the number. As the number increases, the thickness of the bit as well as the plug also
decreases. Eg. Nos.8, 10, 12, 14 etc.
A rawl plug tool has two parts, namely the tool bit and tool holder. The tool bit is made of tool steel and the holder
is made of mild steel. It is used for making holes in bricks, concrete wall and ceiling. Rawl plugs are inserted in
them to fix accessories.

14 15

CITS : Power - Electrician & Wireman - Lesson 1- 4